<s>
SMIF	B-Algorithm
(	O
Standard	O
Mechanical	O
Interface	O
)	O
is	O
an	O
isolation	O
technology	O
developed	O
in	O
the	O
1980s	O
by	O
a	O
group	O
known	O
as	O
the	O
"	O
micronauts	O
"	O
at	O
Hewlett-Packard	O
in	O
Palo	O
Alto	O
.	O
</s>
<s>
The	O
system	O
is	O
used	O
in	O
semiconductor	B-Architecture
wafer	I-Architecture
fabrication	B-Architecture
and	O
cleanroom	B-Application
environments	O
.	O
</s>
<s>
The	O
purpose	O
of	O
SMIF	B-Algorithm
pods	O
is	O
to	O
isolate	O
wafers	B-Architecture
from	O
contamination	O
by	O
providing	O
a	O
miniature	O
environment	O
with	O
controlled	O
airflow	O
,	O
pressure	O
and	O
particle	O
count	O
.	O
</s>
<s>
SMIF	B-Algorithm
pods	O
can	O
be	O
accessed	O
by	O
automated	O
mechanical	O
interfaces	O
on	O
production	O
equipment	O
.	O
</s>
<s>
The	O
wafers	B-Architecture
therefore	O
remain	O
in	O
a	O
carefully	O
controlled	O
environment	O
whether	O
in	O
the	O
SMIF	B-Algorithm
pod	O
or	O
in	O
a	O
tool	O
,	O
without	O
being	O
exposed	O
to	O
the	O
surrounding	O
airflow	O
.	O
</s>
<s>
Each	O
SMIF	B-Algorithm
pod	O
contains	O
a	O
wafer	B-Architecture
cassette	O
in	O
which	O
the	O
wafers	B-Architecture
are	O
stored	O
horizontally	O
.	O
</s>
<s>
The	O
bottom	O
surface	O
of	O
the	O
pod	O
is	O
the	O
opening	O
door	O
,	O
and	O
when	O
a	O
SMIF	B-Algorithm
pod	O
is	O
placed	O
on	O
a	O
load	O
port	O
,	O
the	O
bottom	O
door	O
and	O
cassette	O
are	O
lowered	O
into	O
the	O
tool	O
so	O
that	O
the	O
wafers	B-Architecture
can	O
be	O
removed	O
.	O
</s>
<s>
Both	O
wafers	B-Architecture
and	O
reticles	O
can	O
be	O
handled	O
by	O
SMIF	B-Algorithm
pods	O
in	O
a	O
semiconductor	B-Architecture
fabrication	I-Architecture
environment	O
.	O
</s>
<s>
Used	O
in	O
lithographic	O
tools	O
,	O
reticles	O
or	O
photomasks	B-Algorithm
contain	O
the	O
image	O
that	O
is	O
exposed	O
on	O
a	O
coated	O
wafer	B-Architecture
in	O
one	O
processing	O
step	O
of	O
a	O
complete	O
integrated	O
semiconductor	B-Architecture
manufacturing	I-Architecture
cycle	O
.	O
</s>
<s>
Because	O
reticles	O
are	O
linked	O
so	O
directly	O
with	O
wafer	B-Architecture
processing	O
,	O
they	O
also	O
require	O
steps	O
to	O
protect	O
them	O
from	O
contamination	O
or	O
from	O
being	O
the	O
source	O
of	O
contamination	O
in	O
the	O
litho	O
tool	O
.	O
</s>
<s>
SMIF	B-Algorithm
is	O
typically	O
used	O
for	O
wafers	B-Architecture
no	O
larger	O
than	O
200mm	O
,	O
the	O
equivalent	O
for	O
300mm	O
wafers	B-Architecture
being	O
the	O
FOUP	B-Algorithm
(	O
Front	O
Opening	O
Unified	O
Pod	O
)	O
.	O
</s>
<s>
The	O
greater	O
flexibility	O
of	O
300mm	O
wafers	B-Architecture
means	O
that	O
it	O
is	O
not	O
feasible	O
to	O
use	O
SMIF	B-Algorithm
technology	O
and	O
designs	O
for	O
300mm	O
,	O
hence	O
the	O
reason	O
for	O
the	O
emergence	O
of	O
FOUPs	B-Algorithm
.	O
</s>
<s>
Several	O
FOUP	B-Algorithm
SEMI	O
standards	O
,	O
including	O
SEMI	O
E47.1-1106	O
,	O
are	O
related	O
to	O
both	O
300	O
and	O
450mm	O
wafers	B-Architecture
.	O
</s>
